Portable power-driven tool



Aug. 28, 1951 F p, FORSS 2,566,183

PORTABLE POWER DRIVEN TOOL Filed May 29, 1947 I w V I -Patented ug. 28,419511 PORTABLE POVVER-DRIVEN TOL Frithiof P. Forss, Aurora, Ill.,assigner to Skilsaw, Inc., Chicago, Ill., a corporation of DelawareApplication May 29, 1947, Serial N0. '751,245

(C1. lli-421) 2 Claims. l

`"Ihe present invention relates tc improvements in a rotary power drivenportable tool.

Heretofore in tools of this nature it has been customary to arrange apower motor and the driven shaft in axial alignment, or if a gearreduction was required the motor and shaft might be olset to permit theintroduction of a gear train therebetween but the shaft and motor werestill arranged one behind the other. These tools have operated well inopen or unconned spaces but in restricted spaces their use is limitedunless sacrifices are made with respect to bearing mounte ings, wear onparts, power and stability.

In power driven screw drivers it has heretofore been thought necessaryto support the clutch mechanism and driven members from only a bearingmounted above the clutch members. The elongated driven members extendingoutwardly therefrom cause undue wear on the bearing member and permits atool attachment to wobble preventing accurate precise work as the partswear. Normally toothed clutches have been used with tooth breakage,expense and undue friction and heat.

One object of the present invention is to provide a portable power toolthat may be used in normally inaccessible spaces.

Another object is to provide a portable power tool that will be subjectto less wear and have greater stability than those heretofore known.

`Another object of the present invention is to provide a portable powertool within a small frame but with large spindle bearings spacedrelatively widely apart to minimize wear.

.-A further object is to provide a portable power toolthat is light,compact and can be balanced in the palm of the operator and that yetretains the normal power of longer, heavier tools.

Yet another object of the invention is to pro- Videa portable power toolsuitable for driving screws, running nuts or the like with an improvedclutch mechanism that is less subject to breakage and over-heating.

A still further object of the invention is to provide a portable powerdriven tool with a clutch mechanism having less friction between theparts and that is relatively simple and inexpensive to manufacture.

A still further object of the invention is to provide a portable powerdriven tool for driving screws or nuts havinga spindle supportingbearing between the clutch mechanism and the work holding means tocentralize and stabilize the spindle while in operation.

Other objects will be pointed out hereinafter with specific reference tothe attached drawings wherein one embodiment of the invention is setforth for purposes of exemplication.

In the drawings:

Fig. 1 is a view in vertical section through a tool embodying theinvention.

Fig. 2 is an enlarged view in section of two of the clutch members at aangle to the view shown in Fig. l.

Fig. 3 is a view taken on line 3-3 of Fig. 1 and Fig. 4 is a View takenon line -Ll of Fig. 1.

In achieving the objects of this invention, applicant has conceived of anovel arrangement of parts whereby the power and stability ot the normaltwo hand operated portable electric or pneumatic drill, screw driver 0rnut runner is incorporated into a compact, light tool that will fit thepalm of an operator and can be operated by one hand.

In accomplishing this the overall length of the tool has beenconsiderably reduced to little more than the length of the motor byplacing the driven spindle in a side by side parallel relationship withthe motor. Heretofore attempts to reduce length of tools have meant thereduction of the length of the spindle with a sacrifice of supportingbearings or spacing the bearings so closely together and adjacent thework holder that there has been undue wear on the bearings and aconsequent wobble in the spindle shaft.

In applicants invention the spindle may be as long or slightly longerthan the required motor and the 'bearing mounting may be widely spacedgiving more stability and much less wear. Also the gear train instead ofbeing spaced axially between the motor and spindle may instead bemounted in the normally waste space of the handle portion and cap theends of the spindle and motor shafts, likewise reducing length withoutlosing power or efficiency.

Where used in connection with driving screws or running nuts normally aclutch mechanism is incorporated wherein oppositely disposed clutchteeth may ratchet over each other when a predetermined torque has beenbuilt up. Unwanted heat is created by the friction of the parts and theteeth are subject to breakage with consequent repair and expense. Thepresent invention contemplates the use of roller members between theclutch members, eliminating tooth breakage and minimizing friction. Theroller members may fit partially into oppositely disposed pockets ordepressions in the clutch faces. Upon the building up of a predeterminedtorque one clutch face will ride up over the roller members and itsdepressions will ratchet over the roller members in the depressions ofthe other clutch face. To retain the roller members in one clutch face,the depressions may be made slightly deeper in that face.

With reference to the drawings, it will be noted that the invention isdisclosed with reference to a pneumatically powered tool. Housing I!! isdivided into a motor chamber l2 in which is mounted a rotor it, and aspindle chamber I6 in which is mounted a spindle mechanism generallydesignated as I8.

A rear handle housing member 2U closes the rear portion of housing Itand contains a gear train 22.

At the lower end of handle housing 2D there is an air inlet nipple forattachment to the usual pneumatic air hose. Upon pressing the triggermechanism 26 the valve ball 2l is pressed away from its closed positionas shown against the `pressure of spring' allowing air under pressure topass into the motor chamber l2 and operate the rotor I4. The air inletmechanism and rotor and their operation are described in my cependingyapplication Serial No. 618,047 led September 22, 1945, now Patent No.2,545,453, and form no part of my present invention.

Rotor l has a shaft and pinion l5 extending rearwardly thereof andsubstantially into `the rear handle portion. Gear train 22, suitablymounted in the handle portion, is operatively connected to pinion l5 atone end and at the other to gear IS formed on the rear end'of spindleI8.

This spindle is mounted parallel to the axis of rotor l-l and alongsidethereof. At its rear it is mounted in bearing 3i? in housing it and atits forward end it is rotatably mounted in bearing 3,2 spaced Widelyfrom bearing Sil and giving stan bility through the entire length of thespindle, The spindle includes the shaft 3d extending into and slidablyand rotatably supported in sleeve member 36, the latter being madehollow for this purpose. Shaft 3d has a plurality or" clutch teeth vt8formed therearound for cooperation with clutch teeth 39 formed on theopposed face of clutch member iii-. rilhis clutch member :iii is keyedto the inner end or" sleeve 35, so that it may rotate with respectthereto but cannot move axially in relation to the sleeve, through meansof a number of balls 2 fitting half in each of circumferential groovesit and ifiin the clutch member il and sleeve 35 respectively. Screw plugQ5 (Fig. 2) closes an opening in the clutch vmember through which theballs are inserted into the grooves on assembly.

A further clutch member' is slidably mounted to sleeve '35 but keyedagainst rotation relative -^iereto through the provision of two sets ofball keys 113i, il fitting half in each or" longitudinal grooves it andt of the sleeve 3e and clutch member 4t respectively-as shown in Fig. 2.

Spring member 5u encircles sleeve 36 and abuts at one end against washer5l adjoining bearing 32 and at its other against clutch member forcingthe latter normally up against its opposed clutch member as shown inFig. l. The opposed i'aces or these clutch members t and Il@ have aplurality of oppositely disposed conical depressions 52, 53yrespectively. Depressions 52 in the face o clutch member 135i may be ofa simi- `lar size to depressions E but preferably are of a greater depthas through the use of counter bores .54 so that a vgreater portion Vofroller members balls 55 may be receivedV Within the confines of theclutch member 4) depressions than within the depressions of clutchmember 46.

For instance it has been found among other things that with the use ofballs 55 of a quarter inch in diameter that a satisfactory ratchetingclutch eiect may be produced if the sides of the depressions have a 9Goangle and a ball 55 projects .15o inch from-the face of clutch'memberand .liiG inch from the face of clutch member ilu. In other Words thedepressions 53 preferably are more shallow than depressions 52 so thatmore than Q ol a ball circumference may be received within a depressionE2.

t its lower end sleeve 36 is provided with work holder means such as forthe screw driver bit 58. Between the inner end of shaft 34 and the innerend of hollow sleeve 36 a spring member G can be interposed of astrength suiiicient to normally press sleeve outwardly away from shaft34 to disengag-e teeth 39 of clutch niemberffandnteeth on shaft eX-eeptwhen thetool yis miope-ration.

Also shown is a finder housing B2 receiving l.a finder member slidablyenclosed therein which is normally pressed outwardly to :cover the endof bites by spring vmembere thatabuts :against the inner end of findere4 and against threaded clamp ring that screws into the forwardaend or'housing le to hold the spindle lassemblage together and receives and:holds the ndermcusing in proper relationship.

The tension oi spring 5i! and the consequent pressure between clutchmembers 4Q and i116 may ne adjusted by tension nut lil threaded tosleeveit and abutting against sleeve i2 which moves upon tightening nut l@ toforce the washer 5J against spring 5u compressing the same.

ln operation when motor I4 is started as rby pressing triggerl shaft 34of spindlerevolves by means of the gea-r train 22 'located .at fthe ofthe motor and spindle and jsubstantialh,7 in the handle .portion of thetool. As 'the tool is pressed against a work piece `such Vas aser-ew theiinder housing willbe retracted slightlygper- `mitting the bit Vto comeinto contact with tthe screw kerf.

Further pressure presses the rbit and sleeve member 3E and its accessoryclutch members inwardly against the vaction of spring V:60 until teeth3Q on clutch member 40 engage with'ateeth 33 on shaft 3ft. Clutch member140 then commences to rotate with shaft 34, vrotating clutch member itwith it through .means `of `the fballs 55 seated in opposed depressions.'52 .and '53..in the clutch members. As clutch member flwis keyed. tosleeve 36 `through the Aballs iM., the sleeve 35 rotates `driving thebit member T58.

When a screw is tightened to a predetermined degree, the torque exertedon clutch v'members and @El willcause 'the clutch member 46 having theshallower depressions 53 to ride :up against the pressure of spring 50on balls Y55 and over the same snapping over and on tothe iba-Hsin theirrespective depressions 52 in ya ratcheting action, driving home thescrew and Warningfthe operator to relieve the pressure as `the :screw-is drawn tight. The balls of course ,are retained in their respectivedeeper depressions `5i.' with shallower depressions :5-3 Aratcheting-thereoven It has been found that there is much lessifriction and wearthrough the `use of -these bal-ls :that may roll than through the use-of-ratcheting toothed clutches and much Ilessheatfis developed.

Heretofore to applicants Aknowledgeonly one bearing member such as 30has been used in tools of the type shown in an eiTort to save inover-all length. Because of the arrangement of parts stability has beenincreased and overall length reduced even with the insertion of anadditional bearing member 32 spaced substantially from bearing 30 andadjacent the work holding means.

While one embodiment of the invention has,

been shown and described, other embodiments Will be apparent to thoseskilled in the art Without departing from the spirit or scope of theinvention.

I claim:

1. A portable hand-held tool of the type described, including a mainhousing having a driving motor and a spindle mounted side by sidetherein in spaced relationship, said motor and spindle having pinionmembers extending to the rear, said spindle pinion being containedWithin the main housing, a rear handle housing in the form of a pistolgrip closing the rear of said main housing, the motor pinion extendinginto said handle housing and a gear train mounted at least in part insaid handle housing and partially extending into said main housingoperatively connecting said pinion members together.

2. A portable hand-held tool of the type described, a main housing, adriving motor including a shaft and a driving pinion extending to therear thereof, a driven spindle mounted alongside of and in spacedsubstantially parallel 6 relationship to said motor, and having Workperforming means at its forward end and a driven pinion extending to therear thereof, all of said aforementioned parts being mounted within themain housing, a gear train operatively connecting said motor and spindlepinions, a rear housing in the form of a pistol grip, and means formounting said gear train partially in said rear housing and partially insaid main housing.

FRITHIOF P. FORSS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,217,815 Payne Feb. 27, 19171,407,622 Backscheder Feb. 21, 1922 1,683,715 Erban Sept. 11, 19281,789,559 Meunier Jan. 20, 1931 1,858,276 Miller May 17, 1932 1,864,844Meunier June 28, 1932 2,127,855 Baumgratz et al. Aug. 23, 1938 2,152,517Whitney et al Mar. 28, 1939 2,184,394 Moretti Dec. 26, 1939 2,209,155Fagg July 23, 1940 2,506,835 Johnson May 9, 1950 FOREIGN PATENTS NumberCountry Date 751,817 France Sept. 11, 1933

